Quick Hits

EPISODE 3 — Connections, Physical Protection, Clean Surfaces and Substation Fences (270.8, 270.10, 270.12, 270.14)

Slide 1 — Hook "Rounding out Part I — how grounding connections are physically made, and a section unique to this article: substation fence grounding."

Slide 2 — 270.8, 270.10, 270.12

• 270.8: EGCs, grounding electrode conductors, and bonding jumpers connect via listed pressure connectors, terminal bars, exothermic welding, proper machine screws, or other listed means. Solder-only connections are NEVER allowed.

• 270.10: Ground clamps/fittings exposed to physical damage need to be enclosed (metal, wood, or equivalent).

• 270.12: Paint/lacquer/enamel coatings have to be removed from contact surfaces before grounding/bonding — OR use fittings specifically designed to make that removal unnecessary.

Slide 3 — 270.14 Substation fences & metal structures

• Metal fences within 16 ft of exposed conductors/equipment need wire-type bonding jumpers: at every corner, every 160 ft along the fence, on both sides of overhead conductor crossings, gates bonded to their posts, posts bonded to the grounding electrode system, and openings bonded across with a buried jumper.

• The grounding grid has to extend to cover the full swing radius of any gate.

• Exposed metal structures (including guy wires) within 8 ft vertically or 16 ft horizontally of exposed conductors, if touchable, must be bonded to the area's grounding electrode system.

Slide 4 — Quiz + CTA Q: "A metal fence near a substation with exposed conductors needs bonding jumpers at intervals not exceeding what distance?" A) 50 ft B) 100 ft C) 160 ft D) 200 ft

✅ Answer: C — 270.14(A)(1): maximum 160 ft (50 m) intervals, plus at every corner.

CTA: Follow for more daily quick-hit study notes 📚⚡ — That wraps Part I! Part II (System Grounding) starts next episode.

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